Reverse standoff voltage vs breakdown voltage in bidirectional TVS

[Jim from Chicago]

I am comparing two bidirectional TVS diodes, the part we are currently using is this: https://assets.nexperia.com/documents/data-sheet/PESD5V0C1BSF.pdf

The part we potentially want to use as a substitute is this: https://www.onsemi.com/download/data-sheet/pdf/esd5481-d.pdf

Nexperia part lists reverse standoff voltage as max of 5V. But then it also lists the breakdown voltage as typically 10V. I don't understand. Isn't reverse standoff voltage and breakdown voltage the same thing?

The OnSemi part lists "maximum working voltage" as 5V which I assume means the same thing as "Reverse standoff voltage". But then the OnSemi part lists its breakdown voltage as possibly as low as 4.5V for low current (5uA).

I am very confused what the difference is between reverse standoff voltage/maximum working voltage and the breakdown voltage. Can someone please enlighten me? I need to understand this to determine if we can sub in the OnSemi part in the same circuit...

[schmitt trigger]

My understanding is that reverse standoff and maximum working voltages are the same, which means that this is the voltage that can be applied continuously with a minimum amount self heating and current leakage. The keyword is continuously.

On the other hand, clamping voltage is the voltage drop at the maximum rated current, specified for a very short period of time. The reason this voltage is significantly higher, is that all diodes have a dynamic series resistance which adds its I*R drop to the zener voltage itself.

That is my understanding. Somebody may not agree with me.

[brumbarchris]

Actually, the onsemi datasheet is confusing for me too. Outright conflicting, I would say.

On one hand, the IR parameter indicates the maximum current through the diode when 5V are applied to it is 1uA. Otoh, the VBR parameter indicates you could have the possibility of having 5uA through the diode at a 4.5V drop on it.

To me, this is a contradiction, and the minimum VBr at 5uA should be above 5V.

Cristian

[coppercone2]

sounds like you should just test it, you can do it with a momentary contact switch and a power supply